1,561 research outputs found
The Influence of Natural Sounds on California Ground Squirrel (Otospermophilus beecheyi) Vigilance and Predator Detection
Many animals rely on the acoustical environment for functions spanning mate attraction, navigation and predator and prey detection. However, recent research suggests that the context of the acoustic environment can greatly influence the propagation and reception of acoustic signals and cues, potentially interfering with the ability of animals to perceive important environmental cues. Here, we sought to determine whether natural sounds influence vigilance and predator detection in the California ground squirrel (Otospermophilus beecheyi). In a manipulative field experiment, we measured squirrel vigilance behavior under three conditions: playback of river rapid noise, playback of cicada chorus noise and a control, unmanipulated sound treatment. Under each condition, we also measured squirrel flight initiation distance (FID), defined as the distance at which an animal flees from an approaching threat. This behavior was in response to an approaching robotic coyote, which simulated a common predator in our study area. Our study is poised to not only determine whether natural sounds influence key behaviors in a common mammal, but will provide needed information on whether natural sounds and human-made sounds cause similar perceptual limitations and behavioral responses in acoustically-oriented animals. For example, California ground squirrels are known to increase vigilance in the presence of anthropogenic noise, but it has yet to be determined how natural noises, with differing frequencies and power, affect behavior. We hope this study will shed light on the differences between these conditions
Light-Mediated Direct Decarboxylative Giese Aroylations without a Photocatalyst
Previous light-mediated approaches to the direct decarboxylative Giese aroylation reaction have mainly relied on the use of a photocatalyst and a reductive quenching pathway. By exploiting a mechanistically distinct oxidative protocol, we have successfully developed a photocatalyst-free, light-mediated direct Giese aroylation methodology
Nextâgeneration sequencing in precision oncology: Patient understanding and expectations
BackgroundImplementation of precision oncology interventions poses several challenges to informed consent and patient education. This study assessed cancer patientsâ understanding, expectations, and outcomes regarding participation in research examining the impact of matched tumor and germline sequencing on their clinical care.MethodsA total of 297 patients (mean age: 59Â years; 50% female; 96% white) with refractory, metastatic cancer were surveyed, including 217 who completed surveys both before and after undergoing integrated whole exome and transcriptome sequencing as part of a larger clinical research study.ResultsAt baseline, the vast majority of patients expected to receive several potential direct benefits from study participation, including written reports of sequencing findings (88%), greater understanding of the causes of their cancer (74%), and participation in clinical trials for which sequencing results would make them eligible (84%). In most cases, these benefits were not realized by study completion. Despite explanations from study personnel to the contrary, most participants (67%â76%) presumed that incidental germline sequencing findings relevant to noncancerous health conditions (eg, diabetes) would automatically be disclosed to them. Patients reported low levels of concern about study risks at baseline and low levels of regret about study participation at followâup.ConclusionsFindings suggest that cancer patients participating in precision oncology intervention research have largely unfulfilled expectations of direct benefits related to their study participation. Increased focus on patient education to supplement the informed consent process may help manage patientsâ expectations regarding the extent and likelihood of benefits received as a result of undergoing genomic sequencing.This study assessed cancer patientsâ understanding and expectations regarding participation in research examining the impact of matched tumor and germline sequencing on their clinical care. Findings suggest that cancer patients participating in precision oncology intervention research have largely unfulfilled expectations of direct benefits related to their study participation. Increased focus on patient education to supplement the informed consent process may help manage patientsâ expectations regarding the extent and likelihood of benefits received as a result of undergoing genomic sequencing.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147745/1/cam41947.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147745/2/cam41947_am.pd
Controlling soliton excitations in Heisenberg spin chain through magic angle
We study the nonlinear dynamics of collective excitation in a -site
quantum spin chain, which is manipulated by an oblique magnetic field. We show
that, when the tilted field is applied along the magic angle , the anisotropic Heisenberg spin chain becomes
isotropic and thus an free propagating spin wave is stimulated. And in the
regime of the tilted angle larger and smaller then the magic angle, two types
of nonlinear excitations appear, which are bright soliton and dark soliton.Comment: 7 pages 4 figure
Influence of soil minerals on chromium(VI) reduction by sulfide under anoxic conditions
The effects of soil minerals on chromate (Cr(VI)O(4)(2-), noted as Cr(VI)) reduction by sulfide were investigated in the pH range of 7.67 to 9.07 under the anoxic condition. The examined minerals included montmorillonite (Swy-2), illite (IMt-2), kaolinite (KGa-2), aluminum oxide (Îł-Al(2)O(3)), titanium oxide (TiO(2), P-25, primarily anatase), and silica (SiO(2)). Based on their effects on Cr(VI) reduction, these minerals were categorized into three groups: (i) minerals catalyzing Cr(VI) reduction â illite; (ii) minerals with no effect â Al(2)O(3); and (iii) minerals inhibiting Cr(VI) reduction- kaolinite, montmorillonite, SiO(2 )and TiO(2 ). The catalysis of illite was attributed primarily to the low concentration of iron solubilized from the mineral, which could accelerate Cr(VI) reduction by shuttling electrons from sulfide to Cr(VI). Additionally, elemental sulfur produced as the primary product of sulfide oxidation could further catalyze Cr(VI) reduction in the heterogeneous system. Previous studies have shown that adsorption of sulfide onto elemental sulfur nanoparticles could greatly increase sulfide reactivity towards Cr(VI) reduction. Consequently, the observed rate constant, k(obs), increased with increasing amounts of both iron solubilized from illite and elemental sulfur produced during the reaction. The catalysis of iron, however, was found to be blocked by phenanthroline, a strong complexing agent for ferrous iron. In this case, the overall reaction rate at the initial stage of reaction was pseudo first order with respect to Cr(VI), i.e., the reaction kinetics was similar to that in the homogeneous system, because elemental sulfur exerted no effect at the initial stage prior to accumulation of elemental sulfur nanoparticles. In the suspension of kaolinite, which belonged to group (iii), an inhibitive effect to Cr(VI) reduction was observed and subsequently examined in more details. The inhibition was due to the sorption of elemental sulfur onto kaolinite, which reduced or completely eliminated the catalytic effect of elemental sulfur, depending on kaolinite concentration. This was consistent with the observation that the catalysis of externally added elemental sulfur (50 ÎŒM) on Cr(VI) reduction would disappear with a kaolinite concentration of more than 5.0 g/L. In kaolinite suspension, the overall reaction rate law was: -d[Cr(VI)]/dt = k(obs)[H(+)](2)[Cr(VI)][HS(-)](0.70
Formation of ionospheric irregularities over Southeast Asia during the 2015 St. PatrickËs Day storm
We investigate the geospace response to the 2015 St. PatrickËs Day storm leveraging on instruments spread over Southeast Asia (SEA), covering a wide longitudinal sector of the low-latitude
ionosphere. A regional characterization of the storm is provided, identifying the peculiarities of ionospheric irregularity formation. The novelties of this work are the characterization in a broad longitudinal range and the methodology relying on the integration of data acquired by Global Navigation Satellite System (GNSS) receivers, magnetometers, ionosondes, and Swarm satellites. This work is a legacy of the project EquatoRial
Ionosphere Characterization in Asia (ERICA). ERICA aimed to capture the features of both crests of the equatorial ionospheric anomaly (EIA) and trough (EIT) by means of a dedicated measurement campaign. The campaign lasted from March to October 2015 and was able to observe the ionospheric variability causing
effects on radio systems, GNSS in particular. The multiinstrumental and multiparametric observations of the
region enabled an in-depth investigation of the response to the largest geomagnetic storm of the current solar cycle in a region scarcely reported in literature. Our work discusses the comparison between northern and southern crests of the EIA in the SEA region. The observations recorded positive and negative ionospheric storms, spread F conditions, scintillation enhancement and inhibition, and total electron content variability. The ancillary information on the local magnetic field highlights the variety of ionospheric perturbations during the different storm phases. The combined use of ionospheric bottomside, topside,
and integrated information points out how the storm affects the F layer altitude and the consequent enhancement/suppression of scintillations.Published12211â122331A. Geomagnetismo e Paleomagnetismo2A. Fisica dell'alta atmosfera1IT. Reti di monitoraggio e Osservazioni5IT. Osservazioni satellitariJCR Journalope
Rifampicin resistant 'Mycobacterium tuberculosis' in Vietnam, 2020â2022
Objective: We conducted a descriptive analysis of multi-drug resistant tuberculosis (MDR-TB) in Vietnamâs two largest cities, Hanoi and Ho Chi Minh city.
Methods: All patients with rifampicin resistant tuberculosis were recruited from Hanoi and surrounding provinces between 2020 and 2022. Additional patients were recruited from Ho Chi Minh city over the same time period. Demographic data were recorded from all patients, and samples collected, cultured, whole genome sequenced and analysed for drug resistance mutations. Genomic susceptibility predictions were made on the basis of the World Health Organizationâs catalogue of mutations in Mycobacterium tuberculosis associated with drug resistance, version 2. Comparisons were made against phenotypic drug susceptibility test results where these were available. Multivariable logistic regression was used to assess risk factors for previous episodes of tuberculosis.
Results: 233/265 sequenced isolates were of sufficient quality for analysis, 146 (63 %) from Ho Chi Minh City and 87 (37 %) from Hanoi. 198 (85 %) were lineage 2, 20 (9 %) were lineage 4, and 15 (6 %) were lineage 1. 17/211 (8 %) for whom HIV status was known were infected, and 109/214 (51 %) patients had had a previous episode of tuberculosis. The main risk factor for a previous episode was HIV infection (odds ratio 5.1 (95 % confidence interval 1.3â20.0); p = 0.021). Sensitivity for predicting first-line drug resistance from whole genome sequencing data was over 90 %, with the exception of pyrazinamide (85 %). For moxifloxacin and amikacin it was 50 % or less. Among rifampicin-resistant isolates, prevalence of resistance to each non-first-line drug was < 20 %.
Conclusions: Drug resistance among most MDR-TB strains in Vietnamâs two largest cities is confined largely to first-line drugs. Living with HIV is the main risk factor among patients with MDR-TB for having had a previous episode of tuberculosis
- âŠ